Objective: To evaluate the role of MRI in patients clinically suspected to have internal derangement of knee joint and to compare the MRI results with Arthroscopy. Methods: This prospective study was conducted in Department of Radiodiagnosis, Geetanjali Medical college and hospital, Udaipur, Rajasthan. Patients referred from orthopedic and other OPD with suspected internal derangement (IDK) of the knee were investigated with MRI. Total 100 patients were included in the study. After completion of MRI examination, arthroscopy was performed in cases wherever it was indicated. Arthroscopy was used as a gold standard and findings of these 100 cases were compared with MRI Results: It was found that MRI has a diagnostic accuracy of 90%, 90%, 93.5%, 100% and 74.4% for detecting medial meniscus, lateral meniscus, and anterior cruciate, posterior cruciate and osteochondral injuries respectively. Conclusion: MRI has a high diagnostic value in the diagnosis of meniscal and cruciate injuries. MRI is highly accurate in diagnosis of complete ACL tear and PCL tear. MRI is less sensitive than arthroscopy in detecting early chondral injuries.